1. Field of the Invention
The present invention relates to a supporting body for use n an orthodontic appliance which is used as an anchorage for giving a force to a tooth to be treated thereby moving it to a desired position, and an orthodontic method using the same.
2. Discussion of the Background
In recent years, in a field of dental treatment, various orthodontic treatments have been conducted to patients having dental malocclusion.
In the most well-known orthodontic treatment, brackets are fixedly attached on the surface of teeth by a bonding agent, and an arch wire is passed through the brackets. The restoring force generated by the arch wire pulls, pushes, or twists the teeth, so that the teeth are moved to the desired positions in the desired directions in a relative movement. In this manner, the alignment of all of the teeth is corrected. In addition to an arch wire, also used in an orthodontic treatment are rubber rings, resin chains, metallic coil springs, auxiliary wires and the like. As well as the arch wire, these members are engaged to brackets or lingual buttons fixedly attached to the teeth, so as to apply a force to the teeth.
In an orthodontic treatment in which a space between two teeth is closed by accomplishing a relative movement therebetween, a force is applied to these two teeth in a direction toward each other, so that they are moved toward each other. In this case, if the size of these two teeth are different from each other, movement of the larger tooth is smaller, and movement of the smaller tooth is larger.
In many cases, the larger tooth is used as an anchorage in treatment, because the movement of the larger tooth is thought to be smaller. Generally, a molar tooth, especially a first molar tooth (a sixth tooth) is used as an anchorage.
When an orthodontic treatment is conducted on a patient who has lost molar teeth, an artificial dental root (an implant member) is implanted to a portion having no molar teeth. The artificial dental tooth has an abutment on its top end with a path through which an arch wire is passed as shown in U.S. Pat. No. 4,988,292.
There is another technique in which a small implant member is implanted in a maxilla and/or mandibula (or simply referred to as a jaw bone) through an alveolus, and a supporting bar is fixed to a teeth to be treated. The supporting bar extends toward the implant member so as to be brought into contact with the implant. As the implant member serves as a stopper against the supporting bar, further unnecessary movement of the tooth is prevented (see Bousquet, Bousquet, Mauran, and parguel, Vol. XXX No. 5).
As described above, conventionally, the orthodontic treatment has been mainly conducted by a relative movement between teeth. In this treatment, tooth to be treated is moved to a desired position using another tooth (for example, a first molar tooth) as an anchorage. There is a possibility that the tooth used as an anchorage itself is moved from its correct position. Accordingly, complicated processes are required. For example, the tooth used as an anchorage is returned to its original correct position after the orthodontic treatment is completed, or the tooth used as an anchorage is connected to the other tooth before starting the orthodontic treatment in order to keep it to its correct position. Such an orthodontic treatment requires long time and is painful for a patient.
For a patient having a narrow dental arch, a treatment for expanding the dental arch is conducted. In this treatment, a rapid expansion appliance is adopted to rapidly expand the median palatine suture of the upper jaw.
FIG. 34 is a diagram for illustrating an orthodontic treatment using a rapid expansion appliance 40 and a pair of straps 40. One end of each strap 42 is fitted to the side teeth, and the other end thereof is connected to a rapid expansion appliance 40. The rapid expansion appliance 40 has an expansion screw. Turning the expansion screw applies a pushing force to the teeth toward both buccal sides, so that the median palatine suture 41 is expanded in a direction shown by arrows G.
The method using the rapid expansion appliance has a problem. In the treatment, a pushing force is applied to the teeth, and the pushed teeth are inclined toward buccal sides. As a result, the alignment of the teeth is disturbed.
The present invention was made to solve the abovedescribed problems, and the objective thereof is to provide a supporting body for use in an orthodontic appliance. The supporting body is implanted in a maxilla and/or mandibula (or simply referred to as a jaw bone) to be used as an anchorage for applying a force to a tooth to be treated without adversely affecting the other correctly-positioned teeth. The treatment using the supporting body of the present invention requires no complicated processes.
Another objective of the present invention is to provide a supporting body for use in an orthodontic appliance which expands a median palatine suture without imposing unnecessary force to teeth.
Still another objective of the present invention is to provide an orthodontic method using the supporting body of the present invention.